20511409859 has 2 divisors, whose sum is σ = 20511409860. Its totient is φ = 20511409858.

The previous prime is 20511409843. The next prime is 20511409861. The reversal of 20511409859 is 95890411502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20511409859 - 2⁴ = 20511409843 is a prime.

Together with 20511409861, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20511409819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10255704929 + 10255704930.

It is an arithmetic number, because the mean of its divisors is an integer number (10255704930).

Almost surely, 2^20511409859 is an apocalyptic number.

20511409859 is a deficient number, since it is larger than the sum of its proper divisors (1).

20511409859 is an equidigital number, since it uses as much as digits as its factorization.

20511409859 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 129600, while the sum is 44.

The spelling of 20511409859 in words is "twenty billion, five hundred eleven million, four hundred nine thousand, eight hundred fifty-nine".